Abstract
Dikerogammarus haemobaphes is one of several Ponto-Caspian gammarids invading Europe in recent decades. Previously, it exhibited active preferences for habitats associated with another Ponto-Caspian alien, zebra mussel. Now we tested gammarid preferences for living mussels and their empty shells with biofilm and/or periostracum present or absent, to find the exact cues driving gammarid responses. We observed a strong prefer- ence of gammarids for biofilmed shells, even if the biofilm was relatively young (2-day old). However, the biofilm quality, related to the substratum on which it had developed (shells with or without the periostracum, or coated with nail varnish) did not affect their behaviour. In the absence of biofilm, gammarids positively responded to the shell perios- tracum. Furthermore, they clearly preferred living zebra mussels over old empty shells, independent of the presence or absence of biofilm, confirming the importance of a periostracum-associated cue in their substratum recognition. On the other hand, shells obtained shortly after mussels' death were preferred over living bivalves. Thus, the attractant is associ- ated with fresh mussel shells, rather than with living mussels themselves. The ability of alien gammarids to locate sites inhabited by zebra mussels may contribute to their invasion success in novel areas inhabited by this habitat-forming bivalve.
Highlights
Several species of Ponto-Caspian amphipods, including Dikerogammarus haemobaphes (Eichwald, 1841), D. villosus (Sowinsky, 1894), Pontogammarus robustoides
To allow for the fact that biofilmed shells could be preferred by gammarids, we examined the effect of biofilm age
To check the cues associated with living mussels, we presented them to gammarids together with empty shells, with both types of objects biofilmed or cleaned (Table 1k, l)
Summary
Several species of Ponto-Caspian amphipods, including Dikerogammarus haemobaphes (Eichwald, 1841), D. villosus (Sowinsky, 1894), Pontogammarus robustoides 1894) and Chaetogammarus ischnus (Stebbing, 1899), appeared in European inland waters in the twentieth century (bij de Vaate et al, 2002; Jaz_dz_ewski et al, 2002; Konopacka, 2004) Due to their gregariousness and omnivorous feeding habits with strong inclinations for predation, they considerably affect local communities, changing their abundances and taxonomic composition (MacNeil et al, 1997; Berezina & Panov, 2003; Devin et al, 2003). Tolerance to a wide range of abiotic factors, especially salinity, as well as fast reproduction and a predatory nature contribute to the invasion success of the Ponto-Caspian gammarids (Devin & Beisel, 2007; Grabowski et al, 2007). This supports the invasional meltdown hypothesis, stating that an ecosystem becomes more susceptible to new biological invasions with the increasing number of previous successful invaders (Simberloff & von Holle, 1999)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
